staging: lustre: osc: remove obsolete asserts

staging: lustre: osc: remove obsolete asserts

Remove the no longer needed assert in the function
osc_cache_truncate_start(). The assertion in
osc_object_prune() will become faulty with upcoming
changes. The reason this will become a problem is
that there may exist freeing pages in object's
radix tree at the time of osc_object_prune(), which
causes failure at the assertion of (osc->oo_npages == 0).
This patch prevents that problem from happening.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6271
Reviewed-on: http://review.whamcloud.com/16456
Reviewed-on: http://review.whamcloud.com/16727
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>